The present invention relates to an X-ray device for medical examination comprising an X-ray source emitting a beam of X-rays towards an object to be examined, an X-ray detector for receiving the X-rays passed through the object, image processing means, which are connected to the X-ray detector for forming an image of said object, X-ray collimator means, which are arranged between the X-ray source and the object for collimating the beam of X-rays. The invention also concerns a method of improving the image quality of such an X-ray device.
In all such X-ray devices known in the field the image quality suffers from the effects of scattered radiation. This scattered radiation arises when the primary or focal radiation interacts with low-density material. Usually the object is a human patient in which case water and bone are examples of low-density material. Scattered radiation has no specific direction and is detrimental for the resulting image. It causes “fog” in the image thereby reducing the image contrast.
An X-ray device and a method of improving the image quality thereof according to the preamble are described in U.S. Pat. No. 5,878,108. Herein the above-described problem is addressed by arranging an anti scatter grid behind the object and in front of the X-ray detector. Furthermore the recorded image is afterwards corrected for the effects of scattered radiation by means of mathematical image processing methods.
The known X-ray device and method of improving the image quality thereof have the disadvantage that the detected image information is disturbed by the fog and important image information is lost. The corrections made afterwards will furthermore inevitably introduce errors in the resulting image.